Overview

During the weekend of October 17-18, 1998, torrential rains fell over south and
southeast Texas. Up to 22 inches of rain fell which first resulted in deadly flash
flooding from San Antonio to Austin followed by record breaking river floods along several
south Texas rivers the following week. Based on provisional data from the USGS, which is
subject to revision, the flood peak for this event was the highest known peak stage at 15
locations. Tragically, a total of 31 people died during the event (26 drownings, 2 tornado
deaths, 2 heart attacks, and 1 electrocution/drowning). At least 17 of the drowning
victims were in vehicles which were either driven into water or were swept away by rapidly
rising water. Preliminary property damage estimates approached three quarters of a billion
dollars.

The event occurred within the county warning areas (CWA) of three NOAA/NWS field
forecast offices (NWSFO Austin/San Antonio, NWSO Houston/Galveston, NWSO Corpus Christi)
and within the West Gulf River Forecast Center's (WGRFC's) area of responsibility. The
potential for extremely heavy rainfall was anticipated by all offices and by the
Hydrometeorological Prediction Center (HPC) and the Storm Prediction Center (SPC) of the
National Centers for Environmental Prediction (NCEP).

When the heavy rains began in the CWAs of NWSFO Austin/San Antonio and NWSO
Houston/Galveston, both offices began issuing needed flash flood warnings. When the flash
flooding evolved into river flooding, the WGRFC provided good river stage forecasts for
the San Antonio, Lavaca, Navidad, Colorado, San Bernard, Brazos, and San Jacinto Rivers.
However, stage height and timing problems occurred with the forecasts for the Guadalupe
River below Seguin.

The Rain Event

All ingredients for extremely heavy rains came together over south Texas the morning of
Saturday, October 17. A strong upper level trough (figure 1) and surface front were
approaching from the west while a persistent low-level southeast flow of very moist air
(dew points in the mid 70s) covered south Texas (figure 2). Additionally, a plume of moist
mid and high level air was streaming across the area from Hurricane Madeline off the west
coast of Mexico (figure 3).

Figure 2.
Surface station plot at 7 a.m. CDT, Saturday, October 17, 1998, showing persistent
southeast flow of very moist air feeding into south Texas.

Figure 3.
Geostationary Operational Environmental Satellite (GOES)-8 water vapor image at 7 a.m.
CDT, Saturday, October 17, 1998, showing a plume of moist mid and high level air streaming
across south Texas from Hurricane Madeline located off the west coast of Mexico. (Courtesy
of the National Environmental Satellite, Data, and Information Service)

By late Friday, October 16, and early Saturday, October 17, it had become apparent the
ingredients for the heavy rain were coming together for the weekend. The only part of the
puzzle missing was what triggering mechanism would initiate the heavy rain. Forecasters
were keying on the cold front to the west, which would arrive in south Texas late Saturday
or Saturday night, as being the most likely trigger. The 2:35 a.m. Eastern Daylight Time,
Saturday, October 17, Quantitative Precipitation Forecast (QPF) Discussion issued by
NCEP's HPC began with the headline "...EXCESSIVE RAINS ARE POSSIBLE OVER THE CENTRAL
TEXAS HILL COUNTRY LATER THIS AFTERNOON INTO TONIGHT...."

The 3:30 a.m. Central Daylight Time (CDT),(1) Saturday, October 17, State
Forecast Discussion (SFD) issued by NWSFO Austin/San Antonio focused on "MODERATE TO
STRONG CONVERGENCE ALONG THE FRONT..." due in the area Saturday night, October 17, or
early Sunday, October 18, as being the likely focus for heavy rains. The office did issue
a flash flood watch (FFA) early Saturday morning for south-central and southeast Texas
through the entire weekend since conditions were conducive for the development of heavy
rain.

Between midnight and 4 a.m. Saturday morning, October 17, scattered showers and
thunderstorms formed over south Texas well ahead of the front. There was little
organization to the convection until around 5 a.m. At that time, the convection became
concentrated over northern Bexar County (San Antonio) and developed explosively. The
intense convection rapidly spread to the northeast and reached the Travis County (Austin)
area within 2 hours while the southwest portion of the complex remained anchored over
northern San Antonio. The reason for this intense development 12 hours before the front
reached the area is not evident at this time. Research efforts to determine the cause of
this explosive development are beyond the scope of this Service Assessment. Both upper air
and surface data sources are scarce west and south of San Antonio. If forecasters had
access to additional data early Saturday morning, October 17, they would have had a better
chance of identifying the mesoscale forcing features contributing to the early
organization of the intense convection.

The front arrived Saturday night, October 17, and supported continued intense
convection to the east and south of the initial heavy rain location. As the leading edge
of the convection entered the NWSO Houston/Galveston's CWA, several tornadoes were spawned
and were followed by torrential rains. By Sunday, October 18, the heaviest rains were
confined to the NWSO Corpus Christi's CWA along the coastal bend of Texas where several
more inches fell.

As the initial flood wave moved down the rivers Saturday night and Sunday, October
17-18, up to a foot of additional rain fell on the drainages. When the event ended, over
22 inches of rain had fallen over south and southeast Texas, with many areas receiving
over 1 foot of rain.

Figure 4. Total
rainfall amounts over south Texas for the period October 17-21, 1998.
(Courtesy of the NOAA/NWS LMRFC)

The Flooding

Initially, the event consisted of widespread flash flooding in the urban areas of San
Antonio and Austin and along the eastern edge of the hill country in the Interstate
Highway 35 corridor between the two cities. Austin and San Antonio are about 80 miles
apart. By Saturday night, October 17, the flash flooding had moved to the south and east
closer to the coast.

By late Sunday, October 18, the heavy rains had tapered off, and the event then became
a major river flood affecting seven river basins, draining approximately 10,000 square
miles (figure 5). Based on provisional data from the USGS, between October 17 and 22,
record stages were measured at 15 sites (appendix A). These numbers may be revised by the
USGS as they complete their field work before publishing the official record stage heights
for this flood event.

Figure 5. South Texas
river basins that experienced major flooding from October 17-22, 1998. (Courtesy of the
NOAA/NWS LMRFC)

Warning and Forecast
Performance

Except for the river forecasts along the Guadalupe River south of Seguin, warning and
forecast services were good. All field offices, HPC, and SPC were anticipating the
potential for heavy rainfall over south Texas for the weekend. NWSO Houston/Galveston
recognized that the developing situation had many similarities to the disastrous October
1994 flooding in southeast Texas and issued an effective heavy rain outlook statement
Friday afternoon, October 16. NWSO Corpus Christi issued a "South Texas Hazardous
Weather Outlook" (HWO) at 6 a.m. Saturday, October 17, highlighting heavy rain
expected across south Texas during the day.

Although heavy rainfall was expected, a review of the QPFs issued by HPC and the three
field offices for the 24-hour period from Saturday morning to Sunday morning, October
17-18, showed that the rainfall was significantly underestimated by all. The maximum
amount forecasted was 4 inches, however, this amount fell within the first few hours of
the event Saturday morning, October 17. During the day Saturday, the WGRFC did prepare an
updated QPF which attempted to incorporate the early, intense rainfall. However, although
the forecasted amounts were higher, the placement of the heaviest QPF rainfall was west of
where it actually fell. QPF forecasts for this event from all sources provided little
assistance to the WGRFC hydrologists. The magnitude of the rain which fell overwhelmed QPF
contributions to the river forecast demands of this event.

The survey team was impressed with the performance of the NWSFO Austin/San Antonio
staff early Saturday morning, October 17, when the heavy rains developed. The midnight
shift personnel recognized that the extreme rains had begun earlier than expected and
issued a series of well written flash flood warnings. Between Saturday morning and Monday
afternoon, October 17-19, NWSFO Austin/San Antonio issued a total of 163 flash flood
warnings. There were no unwarned flash flood events, and the average lead time for the
warnings was 48 minutes.

Although the loss of life was tragic, NWSFO Austin/San Antonio had flash flood warnings
in effect more than 4 hours before the first flooding related death was reported. Media
and emergency managers in the flash flood region praised the quick work of the NWSFO
Austin/San Antonio forecasters and felt the NWS service had been excellent.

When the WGRFC recognized Saturday morning that a significant and very dangerous event
was underway several hours earlier than had been expected, they went to 24-hour operations
and remained on 24-hour operations through Friday evening, October 23. The WGRFC issued
over 700 site-specific predictions of river stages reaching or exceeding flood stage
during the flooding event. These forecasts were issued to the public by NWSFO Austin/San
Antonio and NWSOs Houston/Galveston and Corpus Christi.

In addition to providing forecasts to the NWS offices for public dissemination, the
WGRFC was in frequent contact with water resource agencies in Texas, especially the GBRA
and the LCRA, to coordinate forecasts and share data. Both the GBRA and the LCRA spoke
favorably of WGRFC's enhanced forecast coordination and communications during this event
after the WGRFC recognized the magnitude and severity of the flood.

Input received from the NWS offices, river authorities, and emergency management
officials indicated the WGRFC forecasts were good for the points along the Colorado, San
Bernard, Brazos, San Jacinto, Lavaca, Navidad, and San Antonio Rivers. However, problems
arose with the stage forecasts for the Guadalupe River below Seguin. For the Guadalupe
River, the river stage forecasts prepared by the WGRFC during the flood were generally too
low and the crests occurred sooner than was forecast.

The river crested at 51.7 feet at Gonzales (flood stage 31 feet) at 6 p.m. Sunday
night, October 18. The river forecast for Gonzales, issued to the public at 5:05 p.m.
Saturday, October 17, from NWSFO Austin/San Antonio and based on WGRFC forecasts,
predicted a crest of 45 to 46 feet Monday night, October 19. This was updated at 1:25 p.m.
Sunday, October 18, to indicate a crest of 51 to 52 feet late Sunday night.

The river crested at 49.8 feet at Cuero (flood stage 20 feet) at 1 a.m. Tuesday
morning, October 20. By mid-morning on Monday, October 19, the river had risen above the
previous USGS flood of record of 41.8 feet (September 1, 1981). The USGS believes the
highest historical stage previously reached at Cuero was 44.3 feet on July 2, 1936, during
a period when no USGS measurement was available. This mark was reached during this flood
by early Monday afternoon, October 19.

The 5:05 p.m. Saturday, October 17, forecast for Cuero, issued by NWSFO Austin/San
Antonio and based on WGRFC forecasts, predicted a rise to 37 feet by midweek. This was
updated at 1:25 p.m. Sunday, October 18, to indicate an expected crest of 40 to 41 feet on
Wednesday, October 21. This forecast remained in effect until 11:45 a.m. Monday, October
19, when the forecast was updated to predict a crest of 44 to 45 feet for Monday night.

Although the river was rising rapidly and ahead of schedule early Monday morning,
October 19, no forecast updates were issued for Cuero until late Monday morning. The USGS
gage at Cuero remained in service during the flood; however, the WGRFC believed the gage
was malfunctioning when it indicated the extremely rapid and unprecedented rises. Early in
the flood, WGRFC received a manual observation at Cuero 1.5 feet less than the USGS gage
report. The USGS had a stream gaging crew on the bridge at Cuero during the flood
measuring the flow of the river. This crew had cell phones but did not relay their
readings to the WGRFC or any NWS office. This input would have confirmed the gage readings
and assisted in adjusting the downstream river forecasts.

As the river rose rapidly at Cuero Monday morning, October 19, local officials and
citizens had to quickly accelerate evacuation actions. They had been expecting the crest
to occur on Wednesday, October 21.

The Guadalupe crested at Victoria (flood stage 21 feet) at 33.85 feet at 2 p.m. Tuesday
afternoon, October 20. At 1:30 a.m. Sunday, October 18, NWSO Corpus Christi issued a flood
warning for the Guadalupe from above Victoria to San Antonio Bay. This was issued by NWSO
Corpus Christi to give officials and citizens of the lower Guadalupe River as much warning
time as possible. This warning clearly stated major flooding was expected. At 11:30 a.m.
Sunday, October 18, NWSO Corpus Christi issued a flood warning for Victoria based on
forecasts received from the WGRFC. This forecast called for a near record crest of between
30 and 31 feet for Thursday, October 22. This forecast was updated at 12:45 p.m. Monday,
October 19, to indicate a crest of 31 feet early Wednesday, October 21. At 9:50 p.m.
Monday, October 19, an updated forecast called for the crest to reach 31.3 feet between
midnight and 6 a.m. Wednesday, October 21. The 9:25 a.m. Tuesday, October 20, forecast
updated the crest to be between 34 and 36 feet and to occur between midnight and 6 a.m.
Wednesday, October 21.

The USGS has determined that the intense rainfall produced flows along the Guadalupe
far exceeding previously known events. Based on preliminary calculations, the USGS
estimates the peak discharge at Cuero was around 400,000 cubic feet per second (cfs).
(This estimate could be revised by the USGS after more information and data are reviewed
and considered before the final computation is determined.) The previous record flow
occurred on September 1, 1981, when 132,000 cfs was measured.

Since USGS gages upstream from Cuero at New Braunfels, Luling, and Gonzales were
knocked out of service as the flood waters moved downstream, the WGRFC was not able to
determine that the amount of water heading down the Guadalupe was approximately three
times the previous known maximum. Had the upstream gages been designed to withstand an
extreme flood, stage data would have been available for a longer period of time during
this event. This additional stage data would have provided valuable information to the
WGRFC concerning the magnitude of this flood.

The WGRFC used Lag/K routing procedures and USGS rating curves to provide guidance for
forecasting the height of the river as the flood moved downstream. The Lag/K routing
procedure is an empirical procedure to simulate the movement of a flood crest downstream
and is based on historical data. The USGS rating curves correlate streamflow and stage
height. The rating curve and the Lag/K routing procedure being used for Cuero were based
on the previous measured flow of record of 132,000 cfs. Although the rating curve and the
Lag/K procedure for Cuero were extrapolated to higher flows, they did not reflect the
extreme nature of this event.

The WGRFC did not update the forecast for Cuero from Sunday afternoon to midday Monday,
October 18-19, because, with the limited information available, they considered the Sunday
afternoon forecast valid.

The river warning messages, based on WGRFC forecasts and issued to the public by NWSFO
Austin/San Antonio and NWSO Corpus Christi, all stressed a major, disastrous flood was
heading down the Guadalupe.

Emergency managers in the Guadalupe River Basin and the media in the San Antonio area
indicated that in this very serious situation, they needed more frequent and accurate
river forecast information.

During the flood, the WGRFC only provided the height and timing of the expected crest.
The media and the public required more detailed river stage information, such as the time
rivers are expected to reach flood stage or how quickly rivers are expected to rise.

NWS Products

The NWS offices performed an outstanding job issuing well worded warnings and forecasts
during this event. The seriousness of the situation was well depicted in the issuances.
Following are the best examples of the wording used.

NWSFO Austin/San Antonio

From Flash Flood Warning issued at 8:27 a.m. Saturday, October 17:

"...THIS IS A VERY DANGEROUS SITUATION! RUNOFF WILL BE RAPIDLY FLOODING
LOW LYING AREAS, STREETS, STREAMS, CREEKS AND RIVERS. MANY ROADWAYS WILL BE CLOSED DUE TO
THE HEAVY RAINFALL AND DRIVING IS NOT RECOMMENDED ACROSS THESE COUNTIES FOR THE NEXT
SEVERAL HOURS...."

From Short Term Forecast issued at 9:03 a.m. Saturday, October 17:

"...EXTREMELY DANGEROUS FLOODING IS OCCURRING... NUMEROUS ROADS, STREETS
AND HIGHWAYS ARE CLOSED DUE TO VERY HIGH WATER OVER ROADWAYS! TRAVEL IS DISCOURAGED, STAY
HOME, DO NOT TRY TO DRIVE UNTIL WEATHER AND TRAVEL CONDITIONS IMPROVE LATER TODAY! ...MORE
IS COMING! CONDITIONS IN SAN ANTONIO ARE LIFE-THREATENING!"

From Flash Flood Statement issued at 10:24 a.m. Saturday, October 17:

"...THIS IS A VERY DANGEROUS AND LIFE-THREATENING FLOOD SITUATION...YOU
SHOULD NOT ATTEMPT TRAVEL THIS MORNING OR EARLY AFTERNOON...STAY HOME UNLESS FLOOD WATERS
THREATEN YOUR LOCATION AND YOU ARE FORCED TO EVACUATE TO HIGHER GROUND...."

NWSO Corpus Christi

From River Flood Statement issued at 12:45 a.m. Monday, October 19:

"TORRENTIAL RAINFALL ACROSS SAN ANTONIO RIVER BASIN WILL RESULT IN MAJOR
FLOODING FROM ABOVE GOLIAD TO THE GUADALUPE RIVER CONFLUENCE. DISASTROUS AND
RECORD-SETTING FLOODING IS OCCURRING UPSTREAM...ALL RESIDENTS FROM ABOVE GOLIAD TO SAN
ANTONIO BAY SHOULD TAKE IMMEDIATE ACTION TO PROTECT LIFE AND PROPERTY. LISTEN TO LOCAL
EMERGENCY PERSONNEL AND FOLLOW THEIR RECOMMENDATIONS."

From River Flood Warning issued at 9:25 a.m. Tuesday, October 20:

"... ***DISASTROUS AND LIFE-THREATENING FLOODING IS OCCURRING IN
VICTORIA***

***LARGE NUMBER OF CITY BLOCKS IN VICTORIA WILL BE UNDER WATER AS THE GUADALUPE
RIVER CONTINUES TO RISE***

PERSONS...ALONG THESE AREAS[lower Guadalupe River and surrounding
creeksandstreams]SHOULD TAKE ALL
PRECAUTIONS TO PROTECT LIFE AND PROPERTY...."

NWSO Houston/Galveston

From River Flood Statement issued at 10:40 a.m. Tuesday, October 20:

"...THIS IS A DANGEROUS...LIFE THREATENING SITUATION AND EVERY PRECAUTION
SHOULD BE TAKEN TO AVOID LOSS OF LIFE AND PROPERTY. MASSIVE FLOODING IS EXPECTED IN THE
CITY OF WHARTON. ...MOTORISTS SHOULD AVOID WATER COVERED ROADS AND FIND ALTERNATE
ROUTES...."

Response
from Emergency Management and Media Customers

Except for those customers along the Guadalupe River south of Seguin who had to respond
to a record high flood crest earlier than expected, response was generally positive. Those
in the areas first hit felt that the NWSFO Austin/San Antonio responded quickly and
effectively to the unfolding event. The Bexar County Emergency Manager said no deaths were
attributed to a lack of warning and evacuation recommendations contained in the warnings
were very effective. The problems experienced by those on the Guadalupe River responding
to this massive flood were due to river forecast or external infrastructure (e.g.,
telephone service) problems resulting from the unprecedented magnitude of this flood.

Public Response

Most of the loss of life occurred when vehicles either were driven into high water or
were swept away by rapidly rising waters. Strong outreach efforts have been undertaken by
NWSFO Austin/San Antonio over the span of many years to educate the public about the
life-threatening dangers of driving into or playing in high waters. These efforts have
been closely coordinated with the media and emergency managers. The city of San Antonio
fines people who drive around street barriers and motorists who must be rescued from high
waters.

Infrastructure
Events at NWSFO Austin/San Antonio

The NWSFO Austin/San Antonio facility was in the midst of the extreme flooding and for
a period of time was completely isolated by flood waters rapidly flowing across the fields
surrounding the building. Water levels came within a foot of entering the building. All
telephone and data link communications were lost from 8:55 p.m. Saturday, October 17, to

1:21 a.m. Sunday, October 18, due to the flooding. NWSFO Austin/San Antonio personnel
exercised great ingenuity by using amateur radio operators (HAMs) and cell phones to
inform surrounding offices that backup was needed. All backup offices responded, and all
NWSFO Austin/San Antonio products were issued as required. The communications outage was
transparent to customers.

Unrelated to the flooding, the NOAA Weather Wire Service (NWWS) suffered a nationwide
outage between 7:50 a.m. and 8:45 a.m. Saturday morning, October 17. Eight flash flood
warnings were issued during the outage and were not transmitted over the NWWS.

Facts, Findings, and Recommendations

Observations

FACT: Based on provisional data from the USGS gathered during the
flooding, 15 locations within the Guadalupe, San Antonio, San Jacinto, Colorado, and
Lavaca River basins recorded flood peaks which represented the highest known peak stages.
These numbers may be revised by the USGS as they conduct additional field studies.

Finding 1: There were unusually rapid rises, primarily below Seguin,
on the Guadalupe River during the event. Questions arose at the WGRFC concerning whether
the river gage readings on the Guadalupe River at Cuero were accurate during the rapid
rise. The WGRFC had received a manual reading at Cuero 1.5 feet lower than the USGS gage
reported early in the flood. The USGS had personnel taking flow measurements on the
Guadalupe River at Cuero during the flood. These crews had cell phones but did not relay
their readings to any NWS office. These measurements would have provided valuable
information regarding the accuracy of the gage readings.

Recommendation 1a: The WGRFC and NWSFO Austin/San Antonio should meet
with the USGS in Austin to develop better coordination methods.

Recommendation 1b: At the national level, the USGS and the NWS should
agree on procedures to improve real-time data coordination.

Finding 2: Early in the flood event, NWSFO Austin/San Antonio was
unable to access by telephone the USGS data collection platforms (DCP) on the Guadalupe
River at New Braunfels and the Blanco River at Wimberly. NWSFO Austin/San Antonio uses
these DCPs to receive real-time river stage height information.

Recommendation 2: NWSFO Austin/San Antonio needs to ascertain why
needed data was not available and take steps to ensure the data is accessible during flood
events.

RFC Models and Guidance

FACT: During the flood event, WGRFC was open 24 hours a day from 6
a.m. Saturday, October 17, through 10 p.m. Friday, October 23. During this period, WGRFC
issued over 120 forecast products, including over 700 site-specific predictions of river
stages reaching or exceeding flood stage.

FACT: QPF forecasts issued by HPC and the three field offices
significantly underestimated the rainfall for the 24-hour period from Saturday morning to
Sunday morning, October 17-18. The WGRFC prepared an updated QPF forecast to incorporate
the early, intense rain of Saturday morning. Although the forecasted amounts were higher,
the placement of the heaviest QPF rainfall was west of where it actually fell. The QPF for
this event from all sources provided little assistance to the WGRFC hydrologists. The
magnitude of the rainfall overwhelmed QPF contributions to the river forecast demands of
this event.

FACT: The river stage forecasts on the Guadalupe River below Seguin
were generally too low and the crests occurred sooner than were forecast.

FACT: The USGS has preliminarily determined that the peak discharge at
Cuero during this event was around 400,000 cfs. (This estimate could be revised by the
USGS after more information and data are reviewed.) The previous measured flow of record
was 132,000 cfs.

Recommendation 3a: Using discharge data from this flood obtained from
the USGS, the WGRFC should update the LAG/K routing procedures and rating curves used on
the Guadalupe River.

Recommendation 3b: WGRFC should determine whether a hydraulic routing
technique is appropriate for use on the Guadalupe River and other similar rivers in the
WGRFC area.

Finding 4: Emergency managers in the Guadalupe River Basin and the
media in the San Antonio area require more frequent updates of river forecasts and flood
warnings.

Recommendation 4a: The WGRFC should update forecasts and issue river
forecast products at least every 12 hours, or more frequently as needed, for all locations
where a river is rising and is forecasted to be above flood stage. This update cycle
should continue until the river has crested.

Recommendation 4b: NWS should consider requiring more frequent updates
of River Forecast Center's products during floods as a national policy.

Finding 5: WGRFC issues plain language forecasts which contain the
crest stage (e.g., 34 feet) or a crest stage range (e.g., 34-35 feet) and the date and
time the crest is expected. There is no information about when the river will reach flood
stage or how quickly the river is expected to rise. The media and the public need
additional information, such as when a river is expected to go above flood stage, prior to
the crest.

Recommendation 5: WGRFC should issue all river forecasts in time
series format in Standard Hydrometeorological Exchange Format (SHEF) for use in formatting
NWSFO/NWSO products to inform the public of the timing of river rises.

Local Offices
Warnings/Forecasts

FACT: Eleven deaths occurred in the city of San Antonio. All deaths
were the result of attempts to drive through flooded streets and roads. NWSFO Austin/San Antonio had flash flood warnings in effect over 4
hours before the first flooding related death was reported. NWS Austin/San Antonio issued
57 flood and flash flood watches, warnings and statements concerning Bexar County (San
Antonio) from Saturday morning through Sunday noon, October 17-18. The San Antonio media
and emergency managers complimented the NWS support in this event.

FACT: NWSO Houston/Galveston issued a "Heavy Rain Outlook"
at 3:11 p.m. Friday, October 16, and at 4:30 a.m. Saturday, October 17, highlighting the
potential of heavy rains over southeast Texas over the weekend. NWSO Corpus Christi issued
a "South Texas Hazardous Weather Outlook" at 6 a.m. Saturday, October 17,
highlighting heavy rain expected across south Texas during the day.

Finding 6: Highlighting the potential for heavy rains by the issuance
of an outlook by NWSFOs/NWSOs several hours before a flash flood watch is issued is an
effective method to increase awareness of a potentially serious flood situation.
Presently, the issuance of heavy rain outlooks is optional.

FACT: NWSFO Austin/San Antonio routinely
issues a "Hazardous Weather Outlook" twice daily to highlight any expected
hazardous weather (including heavy rain) during the following 24 hours. Each outlook
contains prepackaged information concerning scheduling of the product and sources for
receiving this and other outlooks.

FACT: SRH instructions (SRH ROML [Regional Operations Manual Letter]
S-11-97, May 27, 1997) indicate the HWO should include a statement referring customers to
adjacent office's products for more detailed information for nearby areas. Examples in the
ROML imply the referencing information should only be one or two lines in length.

Finding 7: The amount of the prepackaged information contained in each
NWSFO Austin/San Antonio HWO detracts from the message of the day information contained
within the product. The routine issuance of the HWO reduces the impact of the message when
significant events are expected.

Recommendation 7: After consultations with customers, NWSFO Austin/San
Antonio should consider issuing their HWO only when significant events, such as heavy
rains, are expected. In addition, the amount of prepackaged information should be reduced.

FACT: The use of strongly worded statements was noted by the media and
emergency managers as an effective way to communicate the severity of the flooding. The
following statements were repeatedly used by the media in warning the public.

-- "Major life-threatening flood."

-- "This is an extremely dangerous situation."

-- "Most flood fatalities occur by driving into low
water crossings. Do not drive into low water crossings."

-- "Evacuate the _____ area."

Systems

FACT: The Advanced Weather Interactive Processing System (AWIPS) was
used very successfully by NWSO Houston/Galveston. The river basin responsibilities were
split between two people working at two different AWIPS workstations. With the
"Hydroview" capability, they were able to quickly and efficiently assess the
situation at hand, monitor the progress of the flood, quality control the forecasts, and
provide timely customer services. With AWIPS, the MIC estimated they were able to issue
the river forecasts from 1 to 2 hours ahead of the issuance times noted during previous
floods of this magnitude.

Communications

FACT: HAM radio operators played a key role in passing NWS messages
and warnings during this event. Approximately 80 HAMs maintained a week-long 24-hour
network of communications which involved NWS, Red Cross, Salvation Army, and numerous
emergency management staffs. In at least one instance, an experienced operator noted the
emergency management staff in a nearby community had not become aware of the need for
immediate evacuation along a rapidly rising creek and took it upon himself to warn the
staff. His quick reaction and the staff's immediate start of evacuation saved lives.

FACT: At 8:55 p.m. Saturday, October 17, NWSFO Austin/San Antonio lost
all telephone communications due to the flooding in the vicinity of the office. The staff
used cell phones and HAM radio communications to request the surrounding NWS offices
assume backup responsibilities for NWSFO Austin/San Antonio products. All offices
performed the extra duties in an excellent manner. During the outage, NWSFO Austin/San
Antonio relayed warning information to the backup offices via HAM radio links.
Communications were restored at 1:21 a.m. Sunday, October 18.

FACT: Outside users who were aware of the communications outages
praised all NWS offices involved with the backup. They indicated the backup was
transparent to them, worked very effectively, and resulted in no diminished service.

Internal and External
Coordination

FACT: Internal coordination during the event was conducted effectively
based on interviews with the WGRFC, NWSFO Austin/San Antonio, and NWSOs Houston/Galveston
and Corpus Christi.

FACT: The WGRFC provided an increased level of forecast coordination
and data exchange with the river authorities, especially the LCRA and the GBRA, during the
flood event. The GBRA and the LCRA spoke favorably of WGRFC's enhanced forecast
coordination and communications with them after the WGRFC recognized the magnitude and
severity of this event.

FACT: Flooding is by far the leading cause of weather-related deaths
in the Bexar County and the Greater San Antonio area. An early 1980's study conducted by
NWSFO San Antonio reviewed approximately 30 years of weather-related deaths across all of
south Texas. The study determined that approximately 80 percent of the drownings involved
vehicles trying to cross flooded low areas. Most other drowning victims were children and
young adults being swept away by flood waters while walking along or playing in flooded
creeks and streams. These dangers are emphasized strongly in all outreach programs and
during warnings and watches.

FACT: The city of San Antonio fines $200 to any driver traveling
around a street barrier. In addition, everyone in a vehicle who must be rescued is fined
$400. Still, this has not eliminated the problem of flood deaths. The city is looking for
additional methods, including the use of more effective barriers, to prevent people from
driving into flood waters.

FACT: NWSFO Austin/San Antonio ensures that flood education is the
major thrust of all of its outreach efforts, both in the Bexar County/San Antonio area and
across the CWA. All education and training programs, including spotter training, public
safety and school informational talks, include a discussion of the flood threat. Flooding
is identified as the major cause of weather-related deaths and is depicted with very
graphic slides and video films. Safety rules are strongly emphasized. Surveys are
undertaken by the office after each significant flood event to document the threat and
provide additional audiovisual material for subsequent training programs. Spotter training
and public education programs had been conducted in each of the flood-affected counties
during 1998 prior to this flood.

FACT: Emergency managers interviewed were complimentary of NWSFO
Austin/San Antonio's outreach/education efforts in the area, including the spotter
training, community outreach programs through clubs organizations, school safety programs,
and tours of the NWS office. Interviews the office conducts with the media were also noted
as important education efforts.

FACT:

Many Victoria and Calhoun County officials working the
flood event were well versed in NWS flood operations as a result of a very effective NWSO
Corpus Christi-sponsored flood conference held for those officials earlier in 1998.

Finding 8: The WGRFC has worked with the
LCRA and the GBRA to evaluate the need for additional river forecast locations, and
selected sites are scheduled to be added to the WGRFC forecast system. Additional forecast
locations may still be required to complement those planned.

Recommendation 8: The WGRFC and service
hydrologists from NWSFO Austin/San Antonio and NWSO Houston/Galveston and the hydrologic
focal point from NWSO Corpus Christi should meet with river authorities to discuss
additional river forecast locations.

FACT: The headwaters of the Lavaca and
Navidad Rivers are in Lavaca and Fayette Counties in the NWSFO Austin/San Antonio CWA. The
rivers then flow into Jackson County in the NWSO Houston/ Galveston CWA. The San Antonio
Hydrologic Service Area (HSA) includes all forecast locations on the Lavaca and Navidad
Rivers, including the locations in Jackson County.

Finding 9: Jackson County receives river
warning and forecast information from NWSFO Austin/San Antonio. All other hazardous
weather information is provided by NWSO Houston/Galveston. The Jackson County Emergency
Manager would like to receive all hazardous weather information, including river warning
and forecast information, from NWSO Houston/Galveston.

Recommendation 9: SRH should coordinate
with customers in Jackson County to see if Jackson County would be better served by
transferring HSA responsibility from NWSFO Austin/San Antonio to NWSO Houston/Galveston.

FACT: NWSFO Austin/San Antonio has been a
strong advocate of HAM radio operators' usage by emergency managers. The office has
conducted an aggressive program to encourage HAM radio expansion through south-central
Texas, increasing activity from two networks covering three counties in 1994 to seven
networks covering 26 counties in 1998.

FACT: Interviews with emergency
management officials in Bexar County and San Antonio revealed they received warnings and
forecasts. However, there were cases where telephone lines were overloaded making it
difficult for emergency managers to contact NWSFO Austin/San Antonio.

Finding 10: Emergency managers in the
NWSFO Austin/San Antonio CWA could not call into the office at times during the flood
because phone lines were either busy or out of service due to flood waters surrounding the
office.

Recommendation 10: NWSFO Austin/San
Antonio should continue its efforts to expand HAM radio communications by contacting each
emergency manager in their CWA to re-emphasize the value of using HAMS for communications
with the NWS during major, disruptive events.

FACT: After the telephone circuits in
Victoria became saturated, NWSO Corpus Christi was able to maintain critical
communications with the Emergency Operations Center in Victoria with the help of HAM radio
operators.

FACT: Extensive local and national media
interviews were conducted by the local NWS offices and the regional public affairs
officer. A news release on the record flooding was released to the Texas Associated Press
and local media in San Antonio. An "Opinion-Editorial" (OPED) letter from the
Southern Region Director was released to San Antonio, New Braunfels, Austin, Corpus
Christi, and Fort Worth newspapers.

FACT: A KOA campground located along the
Salada Creek approximately 4 miles east of downtown San Antonio was evacuated as a direct
result of a personal call from the service hydrologist at NWSFO Austin/San Antonio.

Finding 11: Several people interviewed in
the NWSFO Austin/San Antonio CWA were not aware of the NOAA Weather Radio (NWR) Specific
Area Message Encoder (SAME) technology.

Recommendation 11: NWSFO Austin/San
Antonio should add information explaining SAME technology on the current locally produced
NWR brochure.

Dissemination

Finding 12: At 7:50 a.m. Saturday,
October 17, the NWWS suffered a nationwide outage and was out until 8:45 a.m. Eight flash
flood warnings issued during this period by NWSFO Austin/San Antonio were not disseminated
over the NWWS.

Recommendation 12: NWS Headquarters
should determine the reason for the 55-minute outage on October 17 and whether the eight
flash flood warnings were re-transmitted when NWWS service was restored.

FACT: City and county officials, as well as members of the emergency
management and emergency response community in the San Antonio area, complained about the
NOAA Weather Radio 2000 synthesized voice. They could not clearly understand what was
being said.

Finding 13: Several individuals interviewed expressed concern
regarding the NOAA Weather Radio 2000 artificial voice. It is viewed as difficult to
understand.

Recommendation 13: NWS should determine what steps are necessary to
replace the current artificial voice with a voice more natural sounding and easier to
understand.

FACT: The NWR alarm awakened the
emergency managers for both Bexar County and San Antonio early Saturday morning, October
17.

Response

FACT: The mayor of New Braunfels, on
behalf of the city council, sent a letter of appreciation to the staff of NWSFO Austin/San
Antonio. Included in the letter were "...thank you sincerely for your invaluable
assistance in response to the worst flood in our community's history" and "...convey
our deep appreciation to all the staff there who gave so generously of themselves during
this catastrophic event. The expertise of the National Weather Service helped
tremendously. Thank you sincerely."

FACT: The Bexar County Emergency Manager
said the evacuation recommendations in the flood warnings were very effective.

FACT: According to the Bexar County
Emergency Manager, no deaths were attributed to a lack of warning.